The Ista Stainless Steel Check Valve is a compact, durable one-way valve built for aquarium CO₂ systems. It uses a stainless-steel internal spring to prevent water backflow. This helps stop siphoning into and ruining sensitive equipment like regulators and solenoid valves. Additionally, it fits standard 4/6mm aquarium tubing.

Key Features:

• CO₂ Pressure Rated: Engineered specifically to handle the working pressure of pressurized CO₂ setups.
• Spring-Loaded Mechanism: Utilizes a stainless-steel spring for positive closure against backflow.
• Standard Fit: Accepts standard 4mm internal and 6mm external diameter aquarium tubing.
• Directional Flow: Features an arrow stamped on the body to indicate the correct way to install the gas flow.

Usage Notes:

• Not for Standard Air Pumps: Because it requires a minimum opening (cracking) pressure to push past the internal spring, it is generally unsuited for low-pressure standard air pumps and should be restricted to pressurized CO₂ lines.
• Orientation: Make sure the arrow points away from your CO₂ tank and toward the aquarium.